Mad Men is generally regarded by people who lived during the 60s as inaccurate because it overexaggerates or sensationalizes a lot of things about the period. It tends to play best to younger people who think the 60s was an overflowing pot of chain-smoking, stylish clothing, and various -isms and want their beliefs confirmed (but really, a lot of historical fiction is that way - you don't want to see the world as it was, because that would be boring, you want a fantasy).

The Simpsons hasn't been consistently good since something like season 5 but it keeps shambling along like a mostly rotted zombie.

Friday Night Lights wasn't bad as a movie (or book) but the tv series was a total mess despite having a very loud cult following. The writers could never seem to be consistent on the main characters' attitudes or beliefs (e.g., has the coach's family been living there for years, thus having a good grounding in the town's culture, or are they fresh yankee transplants whose minds reel at at the strange ways of these curious western folk...?)

and only old people care about accuracy in a work of fiction.

Also, some people have tendency to think "I didn't live that way, it means noone lived that way" to be a correct assumption.

I thought it was all about Hasslehoff with you Germans. From his "singing" to his TV shows like Knight Rider and Baywatch. Anything he makes is gold to your countrymen and women. I can understand Babewatch, but the rest has me questioning the average German's entertainment preferences. Although, thinking about American Idol and the like, I question the average American's entertainment preferences.

Mythbusters

They're a little too family-friendly for me and their methods and conclusions are sometimes dubious but you'll still have some people taking their word as fact.

That's not to say I don't enjoy seeing a pig corpse collapse into an old-timey diving suit helmet it's just that the show is, indeed, overrated.

I think we are just starved for good sci-fi. The utopian views were the main reason why it took me so long to get into Star Trek. Thankfully, I have the my imagination to fill in that utopian environment with the things I require. Like sending people to death in bright red uniforms. Making people kill themselves in the teleporter. How does the replicator work, Soylent Green? Plus the Next Gen and beyond Klingons help with that utopian feel.

While traveling through Germany a while back, I stumbled on an episode of Deutschland Idol and, I hate to say it, but it made American Idol look downright hip and edgy in comparison. My wife is German and we were visiting her relatives who are all very nice, so I'm certainly not bagging on Germany, but some of their musical preferences are odd to an American if you're not talking about heavy metal :p

game of thrones, books and shows. Very average stuff, i guess people just like overrate what they like

I'm a geek and I find most of the humor funny. Don't like so much when they stereotype geeks, but Sheldon gives me the laugh every time.

Feels like they took some of the quirkiness I displayed as a teenager (and to a much lesser extent, now) and magnified it 10 times over.

I don't get the attraction of Doctor Who either. Much prefer their last foray into the Merlin saga.

Yes, the beginning was like a medieval Smallville, but the show really took off on season 3 when Morgana turned bad.

I found Star Trek rather boring as a TV show, but the message that's hidden beneath many episodes is just so amazing that it kept me going trough its entirety. Except for TOS anyway.

TOS had all those messages though, they're just rather ... blunt with them.

While on the subject of Star Trek, I just want to state that The Inner Light is the greatest episode in the entire franchise.

I'd have to say Game of Thrones. Sure, it's a great show but I personally think it's overrated. It gets more attention than it actually deserves, I think. I do applaud the efforts put into making it possible and I genuinely praise the series for its unique story; but, of course, that's just it.

I just didn't get the Gwendolyn casting. She's kind of attractive, but not someone to be fighting over attractive. Morgana was more attractive than Gwen.
Not to mention James "I want to sleep with every alien in the universe" Kirk, despite what happens to my crew. Got to love TOS for that.

They are about the same for me in terms of attractiveness. Katie McGrath is more classically beautiful, but I find Angel Coulby's more distinctive look quite attractive as well.

However, Katie McGrath was the better actress in the series. She acted the heck out of her role. I wanted to throttle her with my bare hands several times during the show.

Angel Coulby did a passable performance, but she wasn't a stand out for me. Maybe she was miscast, who know...

Maybe if Angel Coulby had been Morgana and Katie McGrath had been Gwenevere, Angel would have been the standout.

Hard to say based on one series.

I have to repeat some that were suggested already, good suggestions:

- Star Trek: The Next Generation. I watched the whole series through for historical purposes, quite boring overall, and it hasn't aged well. Even the actors were overall stiff and bad, that baldie was much better in e.g. the X-Men movies.

- The "new" Battlestar Galactica. The show thinks it is much smarter than what it really was. Using fancy words for which you need a dictionary doesn't make the dialogue smart. It was overall quite boring.

- Lost, yeah. Prime example of a show which is just dragged out season after season until people just stop viewing it, bored of waiting for answers. And I found pretty much all the actors and characters unlikeable (the little I watched it).